Fix null sample in encoder support checking logic in Conversion API (#90)

dev/convert.html

@@ -24,7 +24,7 @@
 			chunked: true,
 			chunkSize: 2**20
 		});
-		const outputFormat = new Mediabunny.WavOutputFormat({});
+		const outputFormat = new Mediabunny.Mp4OutputFormat({});
 
 		const button = document.createElement('button');
 		button.textContent = 'Cancel';
@@ -47,7 +47,7 @@
 			format: outputFormat,
 			target
 		});
-		output.setMetadata({
+		output.setMetadataTags({
 			title: 'Bigggy',
 			artist: 'Buck Bunny',
 			images: [{
@@ -105,7 +105,8 @@
 			},
 			*/
 			video: () => ({
-				discard: true,
+				//discard: true,
+				forceTranscode: true,
 				//codec: 'avc',
 				//fit: 'contain',
 				//frameRate: 27.123,
@@ -128,7 +129,7 @@
 				//height: 100,
 			}),
 			trim: {
-				start: 0,
+				start: 1,
 				end: 10
 			},
 		});